Packing for condenser tubes



3, 1956 s. PENNELLA PACKING FOR CONDENSER TUBES Filed March 5. 1953FlG.l

FIG.3

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SAMUEL PENNELLA IN VEN TOR.

Ufl f ds a s Par n e 2,729,472 PACKING FOR CONDENSER'TUBES SamuelPennella, Pompton Lakes, N. J. Application March 3, 1953,- Serial No.340,125

3 can... or. 285- 1 i This invention relates to surface condensers asused in the condensing of exhaust steam in power plants and moreparticularly to a construction of packing for the tubes of such acondenser which packing may be quickly, easily and inexpensivelyinstalled and will not only prevent leakage of liquid or vaporthroughthe connections of the tube and tube sheets of the condenser butwill eliminate or insulate the tubes from the setting up of electrolyticaction with the consequent deterioration of the tubes, tube sheets andpacking.

The packing of the present invention comprises an insert at the inletend ofacondenser tube which is of material substantially inert to actionof chemicals or acid in the water and forms an insulator againstelectrolytic action, thereby providing a protection for the inlet end ofthe tube with a consequent lengthening of the life of the tube.

With these and other objects in view, as may appear from theaccompanying specification, the invention consists of various featuresof construction and combination of parts, which will be first describedin connection with the accompanying drawings, showing a packing forcondenser tubes of a preferred form embodying the invention, and thefeatures forming the invention will be specifically pointed out in theclaims.

In the drawings:

Figure l is a fragmentary section through a part of a condenser showingthe improved packing applied thereto.

Figure 2 is a longitudinal section of an insert ring employed in thepacking structure.

Figure 3 is an end view of the insert ring.

Referring more particularly to the drawings, 1 and 2 indicate the inletend tube sheet and outlet end tube sheet of a surface condenser, each ofwhich is drilled to provide aligning tube receiving openings 3 and 4respectively. The openings 3 and 4 are counterbored as shown at 5 andthe major portion of the inner wall of the counterbore is roughened inany suitable manner as shown at 6 so as to provide annular corrugationson a major portion of the inner surface of the counterbore.

The packing structure in the counterbore 5 in the outlet tube sheet 2 isof substantially the same construction as the packing disclosed in mycompanion application, Serial No. 340,124 filed March 3, 1953, andconsequently this packing structure 7 will neither be described norclaimed in the present application.

The tube 8 of the condenser which extends from the inlet tube sheet 1 tothe outlet tube sheet 2 asis ordinary in the construction of surfacecondensers projects only part way through the counterbore 6 and it hasits end which is located within the counterbore flared as is shown at 9.However, prior to the flaring of the end of the tube 8 a packing ring 10of highly compressed fiber is mounted in the counterbore 6 about aportion of the tube 8. The packing ring 10 is of material of a naturewhich will swell when wetted so that when it is driven upon the tube andinto the counterbore it will first by the force of this driving actionand its contact with the wall of the counterbore be distorted to form aninitial seal and after being wetted will swell and form a permanentfluid tight seal between the tube 8 and the tube sheet 1. The hardcompressible fiber packing ring 10 is provided with an annular recess 11therein in which is mounted compressible packing 12. The compressiblepacking 12 may be corset lacing, compressible metal packing or anysimilar type of compressible packing. This compressible packing engagesthe tube 3, forming a seal therewith and between the seal and the fiberpacking ring 10 so as to prevent leakage of water into the interior ofthe condenser between the tube sheets before such time as the fiber ringswells. The flaring of the end 9 of the condenser tube 8 serves to holdthe packing ring 10 firmly in position.

An insert packing ring 13 is provided which is constructed of tough,hard plastic of-a phenolic-linen or phenolic-fiber composition such asMicarta manufactured by the Westinghouse Electric and Mfg. Co., orsimilar materials. The material of which the insert packing ring 13 isformed will swell to a certain degree upon being wetted but it will notswell to as great a degree as will the highly compressed packing ring10. The insert ring 13 has its inner end 14 reduced in diameter formingan annular shoulder 15 and the reduced portion 14 which when the insertpacking ring 13 is driven into the counterbore 6 will extend into theflared inlet end of the tube 8 as clearly shown in Fig. 1 of thedrawings. A packing ring 16 of highly compressed fiber which will swellwhen wetted is placed between the shoulder 15 and theflared end 9 of thetube 8 and this ring further provides for a firm fluid tight sealbetween the'tube 8 and the tube sheet 1. The insert packing ring 13being of a tough, hard plastic also forms an insulator for insulatingthe tube 8 from the tube sheet 1 and prevents the setting up ofelectrolytic action between the tube and the tube sheet at the inlet endof the tube. Furthermore, the plastic insert extending into the inletend of the tube further protects the tube from cavitation set up byturbulence of the water at the inlet end and the plastic material ofwhich the insert 13 is made is much less susceptible to corrosion anderrosion set up by the turbulence of the water entering the tube andtherefore the life of the tube at its inlet end is materially lengthenedwith the use of the present packing structure. After the packing rings10 and 16 and the insert packing ring 13 have been wetted they will allswell, merging .into the corrugations 6 and forming a fluid tight sealto prevent leakage of water past the inlet end of the tube into theinterior of the condenser (not shown) between the tube sheets.

It will be understood that the invention is not to be limited to thespecific construction or arrangement of parts shown, but that they maybe widely modified within the invention defined by the claims.

What is claimed is:

1. In a surface condenser the combination of tube sheets having tube endreceiving openings therein of substantially the diameter of the outsidediameter of the tubes and tubes extending from one tube sheet to theother, said tube sheet openings counterbored at their inlet ends to adiameter greater than the outside diameter of the tubes, said tubes attheir inlet ends extending into and only partially through thecounterbores. and having their inlet ends flared outwardly into thecounterbores, packing rings of highly compressed material which willswell when wetted in said counterbores inwardly of the flared ends ofsaid tubes, said packing rings provided with internal recesses,compressible packing in said recesses and engaging the tubes and saidpacking rings to form seals therebetween, second packing rings of highlycompressed fiber which will swell when wetted in said counterbore andagainst the flared ends of said tubes, and insert packing rings of hardtough plastic inserted in said counter- Patented Jan. 3, 1956- boresoutwardly of said second packing rings said second packing rings andsaid insert packing rings forming fluid tight seals with said condensertube sheet upon their swelling when wetted.

2. In a surface condenser the combination of tube sheets having tube endreceiving openings therein of substantially the diameter of the outsidediameter of the tubes and tubes extending from one tube sheet to theother, said tube sheet openings counterbored at their inlet ends to adiameter greater than the outside diameter of the tubes, said tubes attheir inlet ends extending into and only partially through thecounterbores and having their inlet ends flared outwardly into thecounterbores, packing rings of highly compressed material which willswell when wetted in said counterbores inwardly of the flared ends ofsaid tubes, said packing rings provided with internal recesses,compressible packing in said recesses and engaging the tubes and saidpacking rings to form seals therebetween, second packing rings of highlycompressed fiber which will swell when wetted in said counterbore andhaving flat end abutting engagement against the flared ends of saidtubes, and insert packing rings of hard tough plastic inserted in saidcounterbores of said second packing rings said second packing rings andsaid insert packing rings forming fluid tight seals with said condensertube sheet upon their swelling when Wetted, said insert rings havingtheir inner end portions reduced in diameter and providing shoulders forengagement with said second packing rings to hold said second packingrings tightly against the flared ends of the tubes.

3. In a surface condenser the combination of tube sheets having tubeends receiving openings therein of substantially the diameter of theoutside diameter of the tubes and tubes extending from one tube sheet tothe other, said tube sheet openings counterbored at their inlet ends toa diameter greater than the outside diameter of the tubes, said tubes attheir inlet ends extending into and only partially through thecounterbores and having their inlet ends flared outwardly into thecountcrbores, packing rings of highly compressed material which willswell when wetted in said counterbores inwardly of the flared ends ofsaid tubes, said packing rings provided with internal recesses,compressible packing in said recesses and engaging the tubes and saidpacking rings to form seals therebetween, second packing rings of highlycompressed fiber which will swell when wetted in said counterbore andhaving flat end abutting engagement against the flared ends of saidtubes, and insert packing rings of hard tough plastic inserted in saidcounterbores outwardly of said second packing rings said second packingrings and said insert packing rings forming fluid tight seals with saidcondenser tube sheet upon their swelling when wetted, said insert ringshaving their inner end portions reduced in diameter and providingshoulders for engagement with said second packing rings to hold saidsecond packing rings tightly against the flared ends of the tubes, saidreduced diameter sections of said insert packing rings extending intothe flared ends of said tubes and forming seals over the point ofcontact of said flared ends and said second packing rings.

References Cited in the file of this patent UNITED STATES PATENTS1,742,793 Staples Jan. 7, 1930 2,090,266 Parker Aug. 17, 1937 2,420,721Pennella May 20, 1947 2.449,616 Pennella Sept. 21, 1948

